Orthogonal Frequency Division Multiplexing (OFDM) is a technique that provides high-data-rate communications, but it's sensitive to the carrier frequency offset (CFO) caused by the misalignment in carrier frequencies between transmitter and receiver, which results in inter-carrier interference (ICI) and degrades the performance. In this invention, we propose a novel bandwidth efficient coded OFDM system, which not only can reduce the ICI, but also can reduce the peak-to-average-power ration (PAPR) compared with some of the previous schemes.
Several techniques have been motivated to find solutions to reducing the ICI. Among these schemes, ICI self-cancellation and polynomial coded cancellation schemes have attracted a lot of attention due to their simplicity and high robustness against the ICI. In these techniques, each data symbol is transmitted on two adjacent sub-carriers with opposite polarity in order to reduce the ICI. However, the data throughput of these schemes is only half of that of conventional OFDM for all kinds of modulations. The rate ⅔ and ¾ coding schemes have been proposed to improve the data throughput with moderate ICI cancellation, but construction of such codes is extremely complicated. Another scheme is partial carrier filling (PCF), which assigns redundant zero values to certain OFDM sub-carriers to reduce the ICI. However, the data through out of this scheme is also only half of that of conventional OFDM.
Accordingly, there is a need for a novel bandwidth efficient coded OFDM to combat the ICI.